Unmilled rice, while appraised highly because of its excellent nutritive value, is not necessarily welcomed by the consuming public because of processing and storage difficulties.
In light of this, research has been done on effective processing of the unmilled rice. For example, the Japanese Laid-open Patent Publication No. 48357/1980 discloses a method for producing keepable food from unmilled rice, according to which unmatured rice with chaffs swollen with water is dehydrated, then fried in a rotary kiln at a temperature at which the rice chaff is burst open, and pressured between a pair of rolls, while the peeled-off chaffs are removed. On the other hand, the Japanese Laid-Open Patent Publication No. 118361/1980 discloses a method of producing precooked food according to which unmilled rice swollen with water is alpharized by roasting and the peeled-off chaffs are removed.
In the former method, since the chaffs are removed at an earlier processing step, the layer of rice bran containing rice germ, rice germ milk or fat, protein, inorganic matter and vitamins tends to be discarded. Thus it is not possible to completely hold the nutrients of the unmilled rice in the processed food.
In the latter method, the rice is fried and hence can be preserved for a certain time. However, the processed rice needs to be cooked again before service because it is relatively hard and therefore is not necessarily suited as emergency food.
While there are other types of the precooked keepable rice food, these are not generally preferred because they contain chemicals and food additives if they are to be preserved for prolonged time.
These types of processed rice food are not entirely satisfactory because some do not come up to the taste of many, while others are unsuitable for prolonged storage, elevated in costs because of chemicals or food additives, or lack mineral nutrients.